


As the Sea Witch Says...

by EriiErii



Series: Kiransona Collection [9]
Category: Fire Emblem Heroes, Fire Emblem Series
Genre: Animal Transformation, Come Inflation, M/M, Size Difference, Smut, Stomach Bulge, Transformation, merman
Language: English
Status: Completed
Published: 2020-03-14
Updated: 2020-03-14
Packaged: 2021-03-01 02:15:09
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,331
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23147584
Author URL: https://archiveofourown.org/users/EriiErii/pseuds/EriiErii
Summary: Xander regaining his humanity was guaranteed now. After being cursed into the form of a merman, and gifted the cure in the form of a dragon stone, he shouldn't have anything more to fear, as he would no doubt become human again by the morning.And yet, with reminders of the tale of the little mermaid who loved, then lost her life to a love not as assured as she thought, he was kept up that night with second thoughts and concerns of whether or not his assured cure was quite so certain as it seemed. As he shared his bed with Teru that night, he thought he could give himself just a little more certainty to share his love with him, just to make sure.
Relationships: Marx | Xander/Summoner | Eclat | Kiran
Series: Kiransona Collection [9]
Series URL: https://archiveofourown.org/series/1652392
Kudos: 6





	As the Sea Witch Says...

**Author's Note:**

> Thanks for reading! For post updates, questions, art and general random silliness in between, check me out at eriisaam.tumblr.com for more!

"... Ha. (Merde…)"

He had the stone now. He even kept the stone decently close by at a pillow near him, and the chain still tugged lightly between the stone at the pillow and from the rest that hung around his neck. He knew that any moment, he would start changing back from his merman-like state the more the stone took its hold on him, especially once everyone else caught on they specifically needed a dragon stone to aid the process. He had to be rational, put his thoughts and anxieties to rest, and surely by morning, Xander would be returned to his human form. There was nothing else to be done about it all, and little more worth thinking about.

...Except now he was reminded of the way that mermaid was _also_ fairly assured of her love in the prince. Or the way the mermaid failed to have the prince love her back, and so was tempted to choose whether or not to take his life to save her own. Or how, in the end, she followed a love that had little strength or merit, and caused her to die and turn to seafoam. 

He relented that he might've been scared. Xander wouldn't admit it, but even if he wasn't forced to drink a potion that would steal his voice, burn his tongue away, or stab him with the pain of a sword's pierce, he was unsettled enough to still be kept awake that night and left wondering. 

He wanted to be rational. This wasn't necessary. He needed to sleep, not worry and debate over the merit behind the folktales of Teru's world. He even already _had_ this mental debate many times before when the memories of such tales were so fresh, and just as many reassurances he was in good hands.

And yet here he was, wide awake in the middle of the night, staring along Teru's back. Were it not for the summoner willingly sharing the bed with him that night, Xander was sure his anxious thoughts would've been far worse.

He reached his hand over to Teru's shoulder, reminded of his current form still for how his hands retained a low yet obvious webbing to them. He initially had it in him to reach over and grab Teru, but at the last instant, faltered enough to simply lay his hand and brush the summoner's bare skin. 

He immediately took his hand back when he noticed Teru shift a little. At first, he thought Teru stirred, but the longer he watched Teru's movements, the more he thought they seemed too subtle and careful, as if the summoner didn't want to wake _him_ up. 

He had even more suspicions when Teru sighed.

"...Teru… Are you awake?"

Teru hesitated, but when it became apparent Xander was awake as well, he turned to face him. He wasn't expecting Xander to have such a timid look on his face, and he couldn't decide if he was tired or otherwise.

"...Did something happen?" Regardless, he proved to Xander he was awake long enough to be surprisingly alert in fussing over the merman. He reached over to cup his cheek in his hand without a second thought, but while Xander nuzzling his hand and holding Teru's with his own was neither new nor concerning by itself, Teru worried more he seemed a little _too_ eager for the contact. He reacted so fast, it was as if he were touch-starved.

"Mn… I could ask you the same. Is something troubling you?" 

Teru huffed. He appreciated the concern, but for Xander to deflect his own, now he _definitely_ knew something was up.

"Not anything new… So that just leaves whatever was on _your_ mind."

"Ah, Teru… Surely you don't need to exhaust yourself on my account." A part of him _tried_ to be teasing, but all it proved was just how little he was used to doing such even after this long.

"We have all night, Xander…" And Teru didn't buy into the weak act anyways. 

He gave the Nohrian mer-king pause. Even in the face of his hesitance, Teru gave him time to decide for himself what he wanted to do that night, even if, by now, he could no longer brush it off as nothing. 

So he gave in.

He voiced the same insecurities he had of it all as before. He even admitted as much how deeply aware he was of just reiterating his earlier insecurities and how they weren't quite so eased as he initially thought or acted once again. He was pretty sure he rambled part of the way to explaining his concerns, but after being so used to having to be so guarded and strict with his choice of words to a much more critical audience as a king, he took full advantage of Teru taking in his every word without ridicule. It seemed like such a silly thing, and yet, he was realizing how much he needed it.

"So… What would you say is the basic criteria of this…?" 

With Xander's needs and wants made clear, he was relieved enough Teru would humor him, and was grateful beyond words when the summoner would indulge him outright. But as Xander was quickly realizing, he didn't know what he _specifically_ wanted, merely a general idea. The two sat up by then, but as much as he let Teru peck him on the cheek, and returned the gesture similarly, he felt that alone was still far too little.

"Well… what did you have in mind? Do you really have to do only the bare minimum?" 

Teru couldn't answer for him. Of course. Xander nodded in accepting that while Teru would give his body to him for the night, it was Xander who had to decide for himself what he wanted to do with that offer. He sighed and adjusted himself, looming over Teru by virtue of both their height difference and the way he carried himself, but thankful Teru didn't mind it or feel frightened of it. 

So he tried to take the initiative. He telegraphed his gestures well, just to be sure that he wouldn't startle Teru badly enough to transform, too. He brushed the side of his fingers to Teru's cheek, and when he tilted more into his touch, Xander moved closer until their faces held only a few inches of distance.

"Maybe we could start…" He loomed close enough to kiss Teru's cheek with a gentle, small peck. "...there."

"Just that?" Teru couldn't help but smile, but he didn't dare so much as chuckle. He knew _exactly_ why Xander was being so careful with him, and he was as grateful for his cares as he was guilty of what led to him learning to do such.

"No…" Teru could feel how heated Xander's breath was against his cheek, but he hardly flinched, and less so as he felt Xander's breaths highlighting a trail from his cheek, to near his lips. "Here as well."

His kiss was much more bold this time. Compared to the earlier peck, Xander felt assured he made his intentions clear enough that he not just leaned in to strengthen his kiss, but to hold it longer. Teru could feel Xander initially trying to cup his cheek with his webbed hand, but his hand trailed off more along the back of Teru's neck instead, supporting the way Teru tilted his head into the kiss. He could feel Xander lick along his lips, and with very little hesitance, Teru invited his tongue into his mouth.

Teru's cheeks flushed with very little effort. He was barely mindful of either of their tongues, and he barely realized he was leaning back inch by inch, until he startled both of them in his stupor as he fell on his back onto the mattress.

Both of them were left catching their breaths when Xander let Teru fall his way free, rather than chase him down just to hold their kiss. He loomed over him, but didn't act further. Instead, he studied the way his blue sideburns trailed, the rest of the long, black strands sprawled out all over behind him, and more, the way Teru clearly seemed surprised. 

"...I apologize, have I gone too far?" Almost instinctively, Xander took Teru's surprise as coming from a place of fear and discomfort. Initially, he lowered himself with hesitation and seemed quick to give up the earlier mood.

"No." 

But what gave him pause was Teru trying to prove his surprise was more for how he was underprepared, rather than anything on Xander's part. Even if Teru hadn't quite struggled much at all in the process of turning over to sit up, Xander shifted the end of his tail closer by Teru's side, then slipped under him. 

Right. This tail. He didn't doubt his love for Teru, nor the summoner's love in return, but he supposed this debunked the power of True Love's Kiss curing him right away.

"Ha...hahaha~"

But he didn't mind it quite as much right then. He watched the way Teru rolled into the open fins of his tail, and it took Xander little effort to coil his fins and the rest of his tail to slowly capture the summoner and lift him up. To hear the summoner laugh at all, even a little, or to see the way he smiled, it made Xander reconsider there being _some_ good to come from all this after all.

"You are certain?" He wasn’t _quite_ as defeated in his tone this time, but there still remained some skepticism of Teru’s willingness for more. He could feel Teru squirming within his grasp, and initially, Xander wondered if maybe he misjudged Teru’s reaction after all, only to catch on quickly he only seemed to shift just enough to try to free his arm and lean far enough to reach Xander’s cheek. 

“Yeah. I’m sure.”

“Ah Teru…”

He brought the summoner closer to him. He may have still held him with his tail, but even so, he pulled him closer to his chest and nuzzled him. This time, he tried to make a stronger effort not to let his doubts ruin the mood again, but Xander initially wanted to start off gently and still handled the smaller summoner carefully. The temptation grew to go just a little further when he felt Teru’s breaths along his chest, and then his neck.

“Ah~!”

And it spiked worse so when he felt Teru squirming by his chest, but especially when Teru kissed at his neck and sucked the skin there. The summoner freed his other hand from the way Xander’s tailfin wrapped it, and his own breaths grew heated when he could feel his hands running all along his chest, but especially squeeze and massage his breasts.

“Y-you’re already quite daring…” He wasn’t quite breathless yet, but Teru certainly caught his attention well. But then could Teru really handle him when he was no longer treating him as gently? With how Teru was at least proving himself quite willing as it were, Xander was a bit more daring, if just enough to at least test him. He pressed against the summoner more than Teru could push him likewise, and between how he couldn’t match Xander’s strength, combined with how Xander still held him from the waist down with his tail, Xander returned the favor and not only attacked Teru’s neck, but gently nipped at the skin and sucked the whole area. The way Teru’s breaths heated and the way he squeezed whatever he could grip of Xander’s chest did little to dissuade him. He could feel how Teru was far quicker to melt under not just Xander’s attention to his neck, but the way one of the tips to his tailfins snuck its way up in his shirt, rubbing along his back. 

He could hear the way Teru whined, yet tried to make the effort to stifle his moans. No matter what noises they could make, the others were far enough, and in deep enough in their sleep that Xander was certain the only way they would wake anyone up was if one or both of them screamed at the top of their lungs. Regardless, the way Teru clearly tried to hold back no matter Xander’s efforts left the king tempted to see how far he could push Teru’s limits, and how loudly said limits would come out.

And, well… if he was going to be stuck with this tail for the rest of the night, he may as well take full advantage of it. 

“Do you trust me?” Xander’s voice purred softly, and he could see Teru nod to him without hesitation, even if his breaths picked up too much to speak otherwise. Xander unfurled the fins of his tail and loosened his coils just enough to gently settle the summoner down and free him. His fins gently cradled his back to keep him up, but not enough to grab him again. 

“Then relax.” His voice was gentle and soothing, even if Teru’s breaths picked up more from the way he felt the contrast from the skin of Xander’s fingers to the webbing between them as the king felt up along his chest and back to free him from his shirt, then along his hips and legs when he similarly freed him of his pants and undergarments. The whole time he cooed to him, he whispered to him little phrases that he understood some as comfort and others as what he guessed were similar sentiments in Nohrian. Every so often, it wasn’t just Xander’s fingers, webbings or the very tip and edges of his claws he felt, but he could feel the brush of either Xander’s lips, or in some cases, his tongue, all along the skin of his chest and stomach. The only time he pulled away from him was not only after Xander left the summoner completely bare, but stripped out of his own clothes for what his current form allowed him to wear. 

Teru made his feelings stiffly clear. What gave him pause was while he initially watched Xander stripped and trailed his body up and down with little thought of where his human half ended and his mer half began, there was something different to him this time. Previously, what made it easy to ignore the slit was how flat and smooth Xander’s body was from his stomach and down along the transitions to the base of his tail. Now, Xander looked visibly uncomfortable even when stripped down, and with how the immediate area of his slit bulged outward into a prominent, rounded bump, Teru could guess why.

“Xander, wait…” 

“Did you change your mind…?” 

Initially, Xander took Teru’s words to heart too hard and stopped completely. While he froze in place with an uncertain, concerned stare, Teru moved closer to rub along either sides to Xander’s bulging, stressed slit. As the tension of what the walls of his opening gave way to what they were trying so heavily to hold back, what he immediately exposed was the transformed state of Xander’s cock, noticing the shape of how it started narrow and expanded in width and girth closer toward the base. Immediately, Xander seemed far less tense with his cock free and exposed, but was flustered for a completely different reason when he felt Teru reach over, initially to run his fingers along it to inspect it, then wasting very little time outright rubbing and massaging it, unphased of the pre-cum leaking at the tip well before then.

“T-Teru… hold…” He barely kept his voice even as he spoke, but he managed to coax the summoner to stop, even if he still initially had his cock held between Teru’s hands. 

With his earlier suspicions calmed and quelled, he realized that what he _really_ wanted from Teru was not to be taken lightly, and would require just a little more preparation. Just as he was about to turn and slither away a little, Teru released him, but the summoner sat on his knees while watching him.

When Xander pulled a bottle of vulnerary from the drawer, his attention perked more.

* * *

Even if Teru was impressed Xander had some experience, there were hints here and there that this was just as new for him as it was for Teru, especially when taking Xander’s new anatomy changes into account. But, if it was what would ease Xander’s heart and made him happier, Teru was all for it. 

He did feel flustered of being drenched in vulnerary, but he was patient, and he was more inquisitive of the idea than completely turned off. He did have to hold back the urge to kick Xander no matter how well telegraphed he was to slip his fingers inside of him, and his mood fluctuated enough in the sensation that he showed little tells here and there of risking an imminent transformation between his hands sharing vaguely claw-like tips, or how confused he was of the way Xander took pause looking just under his cock for some reason.

And just like that, he went from laying on his back on the bed, to suddenly finding himself picked up within the coils of Xander’s tail once more. This time, Xander didn’t trap his arms, and merely focused his coil just above his stomach and barely over his chest. It was tight enough to secure the summoner, but not enough to squeeze him too tightly as to risk crushing him. Even if Xander’s focus in his tail went more for his coils than for his tail, Teru was quickly overwhelmed with muffled moans when one fin has slipped the very tip of itself into Teru’s mouth to toy with him, while the other fondled him beside his cheek. It took every nerve Teru had to avoid biting him, and he couldn’t help but drool a little for the ways Xander took full advantage of playing and teasing him just a little otherwise between flicking his hair or brushing the skin of his face. He was just barely focused enough to feel the way Xander rubbed either side of his hips and fondled either cheeks of his ass.

And then Teru choked out a loud, startled gasp as he felt Xander shoved his cock into him, still moist and slick from how drenched in vulnerary it was, moreso for how moist his awaiting hole still remained from the magical medicine. He could feel how much the vulnerary was his saving grace in numbing away what could’ve been a far more painful entrance into his hole otherwise, and for what he felt instead, Teru was shuddering and moaning in ways Xander couldn’t help but smirk to.

“It’s alright.” He purred to Teru as he slipped closer along Teru’s back. With their height difference, Teru could feel the back of his head cushioned by either of Xander’s breasts the further the mer-king held him closer to him. To either of their relief, Xander’s dragon stone rested along his back, rather than greet the back of Teru’s head painfully otherwise. Teru gasped in ways that nearly seemed like he choked mid-cry, especially as the more Xander shrunk their distance, the more he felt his cock digging deeper into his hole and force him open the closer to his base he squeezed into him. Teru held his head up and shut his eyes for a moment. His breaths grew harsher and heated as he could also feel his stomach pucker out when Xander’s cock plunged far deeper into him than he anticipated. It was debatable if Xander himself even realized when Teru was losing his nerves to speak even vaguely coherently as Xander cupped and fondled his breasts while looming over him and settling his cheek just beside Teru’s head. 

He could hear Xander try to distract them with sweet nothings in his mother tongue. But even if he hadn’t lapsed into a language Teru couldn’t quite follow anyways, his mind was hazy when all he could focus on was the thrusts Xander’s hips made, repeatedly sliding himself out just a little before thrusting himself back deep into him, continuing the process in slow yet powerful repeated motions that left him choking out a moan every thrust, especially as it repeatedly eased and pushed his stomach in tandem. More of the fin to Xander’s tail went in to his mouth as to keep it open just a little, and for the chunk of Xander’s fin went into his mouth, he felt like even as he _had_ tried to bite Xander’s tail out of reflex of it all, his bite and focus of such was too weak to even break the “skin” of the fin to harm Xander anyways. It was little else like a gag, but Xander was mindful to try not to outright choke Teru all the same.

As Xander’s attention grew stronger and heated, eventually, the tip of Xander’s tail adjusted from coil to fin to focus on loosely coiling the point just below its tip and fin met to wrap around Teru’s cock. It was a loose, clumsy coil, and in a few times, Teru winced at the painful moments Xander initially squeezed him too tight. But eventually, Xander readjusted his hold on Teru to split his attention of pleasuring the summoner as he continued to pound into him from behind. Without his mouth occupied, Teru was left growing louder with far less restraint, and as his thoughts grew murkier in the distraction, his earlier hesitance that previously stifled him were all but forgotten. 

He couldn’t think clearly enough to remember his surroundings after a while. He lost his sense of time, too. He hadn’t even realized himself the times he cried, yelped, or the point at which his tensions gave way and left Xander’s tailfins drenched and glistening in his cum. He was previously aware of the ways Xander growled, moaned and huffed, but the noises they made blended in so much with one another that he hardly thought of how loud Xander grew by comparison.

The only time he became aware of the difference again was when Xander couldn’t help but yell, and Teru was keenly aware of his stomach suddenly hurting more immediately after.

Eventually, Xander stopped. Both of them tilted awkwardly, they were both left near breathless, and he could feel the way Xander shuddered as he still held him. If Xander hadn’t kept him held up by his tail, Teru would’ve collapsed on the bed completely. It left him somewhat impressed the kind of strength Xander had to keep _himself_ standing up, even if just barely so.

He could feel Xander disengage in distancing himself from mounting Teru from behind, or how he held him with his tail. He could feel every moment Xander’s cock was sliding along the walls of his hole for just how tightly he gripped him within. For what little open gap there was between where Xander’s cock narrowed and from Teru’s hole, he felt Xander’s cum leak in excess, leaving him feeling even more drenched than what the vulnerary already did. Xander’s cock retreated back into hiding between his once-more-flat slit, and he took gentler care to lay Teru down against the bed with his tail. But as predicted, Teru ran out of energy to even attempt to sit up. Even without Xander’s cock inside him, his stomach still bulged out, and even when he wasn’t in pain, he could feel the soreness in the area in places he was now keenly aware the tip of Xander’s cock repeatedly pushed while inside him. 

He tried to focus on Xander. He _still_ stubbornly held himself up with his arms, and he had to take a moment to regain himself before slithering lowly by Teru’s side. He watched the way Xander studied him with a look Teru couldn’t tell if _he_ should also be concerned, especially when there were looks Xander flashed bordering on worry and dread.

That look only strengthened when Xander gently reached out and pushed against the bulge of Teru’s stomach, only for the summoner to hastily grab his hand and moaned lowly and painfully. His grip was too feeble to push Xander off, but the message was clear enough to prompt the king to pick him up in the coils of his tail once more.

“...Let’s get you cleaned up, Teru.” 

As clumsy as Xander was in still feeling sore, he carefully made his way to tend to his tired, sore summoner in bringing him with him to draw a bath for the two of them, relieved that no matter how heated the moment, they still remained the only ones awake in the late night. He was careful and gentle in ways he tended to and fussed over his summoner. He was in such a daze as to be barely aware of the specifics, especially as time seemed to flow quickly that night from Teru’s perspective, but he was aware enough of Xander’s love and care for him to trust him. He could barely remember when he fell asleep, but while Teru was delirious from the points Xander tried not to drown him as they bathed, to the point he changed their sheets and dragged him back to bed, he vaguely remembered snuggling into the heated warmth of Xander’s chest as the two slept together once more.

By morning, Xander woke up, still left naked beside Teru, but a human once again. Whether those tales or superstitions held merit or not, or whether the moment they shared last night held any impact for such, it left Xander debating on it, but not quite enough to press the matter. He and Teru woke up enough to dress up once more for the day, but he had more thoughts of his guilt for how sore and in a daze Teru clearly still was that drowned out his thoughts about the ill-fated mermaid of his world’s legends.


End file.
